Using Ultrasound to create complex smart material 3D prints

Ultrasound 3D Printing

The research team have developed the first demonstration of 3D printing of composite materials. Ultrasonic waves produce a pattern of microscopic glass fibres which give the component increased strength. A laser cures the epoxy resin and creates the component

Many of the great innovations in 3D printing have come from university research, whether that is Carl Deckard and his team at The University of Texas at Austin's Mechanical Engineering Department creating SLS or more recently Prof Jenny Lewis and her team creating the multi-material printer company Voxel 8.

The latest academic innovation with great promise comes from the University of Bristol in the UK. PhD student Tom Llewellyn-Jones and his research team have published a paper called Smart Materials and Structures, which details a new process that could help us produce better composite parts with ultrasonically arranged microstructures.

Using a modified SLA process the team have used a laser to cure an epoxy resin at the same time as using ultrasonic waves to arrange glass microfibres to form a reinforcement framework in a material to give it added strength.

Tom Llewellyn-Jones, a PhD student in advanced composites who developed the system, said: “We have demonstrated that our ultrasonic system can be added cheaply to an off-the-shelf 3D printer, which then turns it into a composite printer.”

Reinforcing printed parts with fibres has been a technique popularised by the efforts of the team at MarkForged who use its Mark One printer to lay materials such as Kevlar and Carbon Fibre into the matrix materials to give parts unparalleled strength. The team based out of the Department of Aerospace Enigineering at the University of Bristol think their process goes one step further.

Bruce Drinkwater, Professor of Ultrasonics in the Department of Mechanical Engineering, said: “Our work has shown the first example of 3D printing with real-time control over the distribution of an internal microstructure and it demonstrates the potential to produce rapid prototypes with complex microstructural arrangements. This orientation control gives us the ability to produce printed parts with tailored material properties, all without compromising the printing.”

The research team points to a diverse range of products that already use composite materials in order to gain strength, sporting items like tennis rackets, golf clubs where strength-to-weight ratio is key already use such materials and obviously the aerospace industry is forever seeking stronger lighter alternatives to current materials and productions methods hence the sector's huge investments in 3D printing technologies.

Dr Richard Trask, Reader in Multifunctional Materials in the Department of Aerospace Engineering, added: “As well as offering reinforcement and improved strength, our method will be useful for a range of smart materials applications, such as printing resin-filled capsules for self-healing materials or piezoelectric particles for energy harvesting.”